The invention relates to a book forming and pressing machine comprising a pressing device, a loading device, wherein the loading device includes a loading table and the pressing device includes a number of spaced-apart pressing plates and joint-burning rails. The loading table is equipped with a mechanism that functions to support the book block back and is operatively connected to the shaping operation.
Known book production lines successively combine a book block and a cover in a clocked operation to form a book. A book forming and pressing machine is used for one of the final production steps, for example as disclosed in the German patent document DE 4422783 A1.
The aforementioned document discloses a book forming and pressing machine which comprises a number of pressing devices with thereon arranged joint-burn-in devices, as well as a rotor that is driven intermittently around a vertical axis. The books themselves are supplied via a feed-in station into a pressing device where they are accommodated fully and are formed continuously with the aid of the burn-in rail and remain permanently in the same pressing jaw until they are removed again via the discharge station. Between the feeding in of the book blocks encased in covers and the discharge of the bound and pressed books, the rotor executes some intermittent rotational movements which are utilized as intervals for the pressing and joint burning. In the loading station, the books are divided into the two book flows via a loading rake with associated guide web, so that they are subsequently transported while supported on the side and supported by the loading rake and a counter rake from a loading table equipped with prism bars from below into the opened, stopped pressing device. The prism bars are provided for this with special inserts, designed for round or flat book backs. Format changes for books therefore require machine stops and setup times for replacing the prism plates since the complete machine is provided for safety reasons with a cover which generally has to be removed first. When changing from a flat to a rounded book block back, or when changing to an insert having different dimensions which can be used to achieve a better rounding, the machine must be powered down, the cover opened and the machine subsequently restarted.
With books having a flat or straight back, differently wide support rails are provided as individual bars for which the dimensions are adapted to the thin book format, wherein these bars are screwed immovably into the frame. These are replaced with two straight bars for the wider formats, wherein these are 2 parallel arranged plates for which the narrow longitudinal surfaces point upward once they are fully installed.
According to the prior art, at least one of the plates is installed fixedly in the frame while the second plate can be displaced with the aid of different advancing mechanisms to a defined distance parallel to the first plate. The distance between the two surfaces which point toward the outside corresponds to the book thickness. The book rests with its back on the narrow longitudinal surfaces. With a configuration of this type, thicker books always only rest with the outer region of the book block back on the bars.